Preparation of phosphorus compounds



Patented Nov. 22; 193 2 111 m STA ES 1 THE now oHEMIoAL ooirrrANY, or MIDLAND, tuonrenm a 'ooRP'oRATroNfor mrcnreen 1T0 Drawing;

The invention relates ;to methods for the preparation of halogen compounds of phos "phorus, and has particular regard to anew and improved method for the preparationiof phosphorus oxychloride by first chlorinating phosphorus in a solvent to formphosphorus pentachloride and subsequently reacting upon the latter with water or steam under temperature controlled conditions whereby phos phorus oXychloride is; produced. A m'odifi cation of our improved'method consists, in substitutingfor water in the second step referred to an organic compound containing a hydroxy group, either alone, as in an alcohol or phenol, or in association with a carbonyl group, CO, to form a carboxylic radical, as in the aliphatic or aromatic carboxylic acids.

Such substitutionresults in the concurrent production of either an organic chloride or acid chloride along with phosphorus oxychloride and constitutes an advantageous? method for the preparation of such compounds.

To the accomplishment'of the foregoing and related ends, the invention, then, consists of the steps hereinafter fully described and particularly pointed out in the claims, the following description setting forth in detail but a fewof the various ways in which the I principle of the invention may be used,

Generally speaking, the reactions involved in the present process are asexpressed in the 1 following equations. Equation (1) represents the union of phosphorus and chlorine to form phosphorus pentachloride l 1 zra scizeroi,

The product of the first reaction thenis'combined with water to produce phosphorus oxy; chloride in which R represents either an inorganic ele merit or group, or an organic radical'or group. When R represents an organic radical, it may 'Applic ation fileo Jul s, 192a. Serial No," 377,074;-f3

P mman EDGAR o. BRITTON AND HAROLD R. SLAGH, or. MIDLAND; monienn; ASSIGNORS TO E ma-non or PHOSPHORUS ooMPouivns be either? an" alkyl "or arylgroup, as

hydroxylic compoundempl'oy'e'd is an, alcohol or phenol; and the I-product fisfanqorganic chloride, while ,ingthe-j-se'cond-v(case; the hyv droxylic compound is an-acid, and the product derivedtherefrom is an acid chloride.v

a The direct chlorination ofphosphorus, particularly .whencarried outlon a large scale,

presents, operating difficulties owing/to the avidity with which the'two elementsenterinto combination. Much heat is generated,

and, in factpthe combinatiommayprg d I with explosive violence unless" means are taken to regulate the speed ofthe reaction,

The latter may be most conveniently aiCQOm-L plishedby conducting the reaction in a liquid solvent, andfor SIIChjPLl I P'QSG we have found phosphorus trichlorideor oxychloride, or a mi'xture of the two, best adapted, in that said compounds are producedin thepresent process-and when initially employed as solvent for the. chlorination the separation of reaction products is greatly simplified, Another ad vantage of using a solventjis' that it protects the phosphorus from the actio n of air that may be present :injthe reaction vessel,

H The chlorination; reaction may! ceived as proceeding in two .'successive steps or stages, first producing phosphorus trichlorideand then converting the latterto-the pentachloride, [By suitable regulation of the proportion of chlorine introducedthe rea'cvtion,therefore, may be useda to prepare either the trichloride' or pentachloride or bothof them together in any desired jproportion; When phosphorus *trichloride is initially taken vas solvent, theaddition of a sufficient' A quantity of chlorine wi11 naturally result in the chlorination of the solvent, too,'after' all ofthefr ee phosphorus present has been reacted. In'practice'the chlorination step is not carried through to the point fwh'erephos- V phorus'pentachloride is thefsoleproduct, for

the reason that the reaction mi'xturewould then become solidand in such form would be very difficult to manipulate on account of the highly reactive character of phosphorus pen tachloride and its susceptibility to the action i? tophosphon soxyehloride by reaction With 10f inoisturein' thenir or frl'o m any other source. It islprefer able that the reaction product beof such" composition as'to remain liquid atordina'rytemperaturesin order to i fecilitate the further handling thereof, The

operation is terminated, therefore, While the .mixture still rema'ins in a fluid condition and V trichloride. 7

contains more or less triehloridealong with- :pentaehlor-idew During the chlorination step-the ieinperature'is to be inaintained be;-

" take part in the reaction ifthel'atter'is m ain tai-ned below ithetemperatureiliinitust men tionedi Inspire {case 'feesibleto mien-u nateqllof =th v pentachloride', ii des ined, or 'thereaetion'muy i 1 be-Estopped sl t-ortoifi-eomplete .ohlorinaition, so}

. osphor'us completely to t-he thsit the-eonsistsoia mixture fnig chloride, lpentaohlorideund oxychloridel 1 In thesecond step -orr'stagge f the proeess; wherein the; -intermedi-a te' reaction prod-net containing phosphorus' pentaehlofideinsole: t-ionris reecteiiw ith'water or a 'eompound eonb a'hyd ylg un e e d'an' h Equations ('2) or 3), the exothermic-joker l ureter of the reaction is even more pronounced; f 3o, 7 p I l e raite the violence of the reaetion is equally 4 imperative if' an'y adequate control to .be

and the'need foremploy-ing a solvent to mot} exei cised over the operation If. the tein; per'gtture allowed to rise toi agn 'exeesswe rilegree', due to lack of adeqnatecontroi, the re 7 action between phosphorus pentizehloride and water instead. of taking 'the de'sired course I will l-tendfto proeeedaccording to Equatlon (4 the product pf; which isphosphori'e Lucid mdjnotphosphorusoxychlorideg 11 I r ,(4) -1 c1 mioen iofisnoil 1' The "liquid jxni z zture resultingffrom the hlpr nat nvstep s, ewOr i g advantegeouslyi mplpyed for suehsecondstep While f phosphorus trichloride ,and oxyehlo lriiloiai'e "bothr fimblei i h water, also, asil- Phosphorus pentaeh1oride is present "in the mixture "By adding. only suflioieilt- Water or equivaIent compound to react with-the phosr phoru s i pentaehloride 7 end controlling-the (3.; the principa-l reaction r my be caused to prleeedjsubstantiallyrto the exclusion of the S CQ dhry reactions. However, should such YY secondarynreactions take place to a' c'ertainv extent theproducits thereof will-be converted phosphorus b h riae in means with Equations (7) d r 1 r s) Hg o +ePou-erool w enol Consequently, under suitable control of the" 1 quantities-ofreeetion material's-f'i-ntroduced such amount of phosphorus 'Ehe separation of phosphorus 1 02:; 1 and triehloiide frornthe reaction,- 7 readily accomplished by simple dist The reeox ce zed triehioride he reti solyent-forthe initie ermed nation stepofa succeed I ope riitioiru de-. sired, also, ;the entire 1e tion by adding more phosphorus-thereto{21nd repeating t-lmsame procedure us -before, in this ay'cychngtheproducts of the process until a sufiicient acoum'ulaitionfther fis ob or process may be applied'gfbut it be"; understood that the invention is not limit-ed theretQY I" t fEwample In a suitable lead linedehlorinafiingfvess containing 100 lhsi phosphorusoxychloride WflSPlaCBdBIlbSJyllOW phosphorus; Chlo r 1 p o t may he employed-as solvent 1 01' a succeeding operai eduets 1;

the in:

and of the reaction temperature'in the sec: p 0n age, thefin'a pro ct w l lc n istsubr is 'stantially 1 offgphosphorus oxyehloride i aih'd ch r de s; was present in the mixture a t thebe'ginning 7 5 of-the ste'p, toge'ther with hydrochloric aeicl or equivalent chlopeolnpound, free, froinmgn Vterial inclusion of secondary reactiloii"prod .ue'ts'fl rent the 'chlorihloride; may Else 7 rine Was then passed i11 while the tempera v V ture of the mixture wasinaintained below 0., until a quantity'ofl ilhsihadbeen id'ded; f The reaetionproductthenicontained'approximately lbs. P0015, "lbs. PC1 and 48.7 p v lbs. This nixti reru as thentreated With stirring, with 11 .61bs.;wateresvapor distilled froln'a still connected to thejreetioh vessel, suchintroduction of Water v'aportaking place clui"ing g" e periodofl hourjand the p r r 'be g' ep 'bel w Z (3 4:.6,1bs,- r it telill raitlireof'the niixture behnw avbout 7UP HG} Was-revolved ni' hei eec er rve 7 Fractional distillation ofthe residual mixture i gave 46 lbs. P01 (94.5 percent. yield) i inixturevcontaining 306. grams 110 grams PCl and124 gramsPQl wiis pre 1 and pared as; in Example 1 and "then introduced intoa flask provided with a stirrer, reflux condenser and vapor outlet leading to a con denser and receiveiu During a period of 1; hour 36 grams glacial acetic acid was added, the temperature-beingregulated atabout 46 continued at 70 C. fOI1 'l'10U.1 Ethyl chlo ride distilled from the'reaction mixture and I combined with that of phosphorus ozychloride; the phosphorus pentachloride re C. Thereupon'hea'ting Wascontinued for-1 hour at C. and for A3 hour longer at 68- C. 41 grams acetyl chloride distilled offand was collected, yield 88.2 per cent. Fractiona tion of the residual mixture gave39l grams P001 and 100 grams PO1 A yield of 85 grams 1 0C1 7 was obtained in'addition to the initial charge, amounting to 92.9 per cent. oftheory.

" Ewample A niixt ure consisting of grams and 208 grams PCl was prepared by chlori-- nating phosphorus using P61 as diluent. this mixture 46 grams absolute alcohol was added during a period-of 1 hours, the tem perature being maintained at about 47 (1,.

and after all alcoholowas added heating fwasv grams thereof was collected, corresponding to per cent. yield. On fractionating 145 grams POCl was obtained, amounting to 94.6 per cent. yield,and289 grams PO1 was recovered.

Among the advantages to be gained by operating in accordance with the process of our invention are: (1) a simple and. effective meansfor controlling therea ction in each of the principal steps is afforded :by employ ing a solvent; (2) the separation of thereac-r tion products is greatly simplified by using as solvent an intermediate product or one of the final products of the process, or a mixture r thereof; (3) a high yield of phosphorus oxychloride is obtained; (4) the preparation of organic chlorides or acid chlorides maybe our invention may be employed instead of the one explained, change being made as regards the process herein disclosed, provided the step or steps stated by any of the following claims or the equivalent of such stated step or steps be employed.

distinctly claim as our'invent1 on process of h g n pounds of phosphorus which compriseskreacting phosphorusand a halogen in aliquld e thereforeparticularly point as and I in i medium including atleast one halogenderivative of phosphorus.

2. A' processof' preparing halogen'coni- 7 pounds of phosphorus which comprises reg acting phosphorus and a halogen in a51iquid medium including the l corresponding I phosphorus .trihalide. 1

3. A process of preparlng'halogen com: 7

pounds of phosphorus which comprises react- 7 ing between phosphorus and; a halogen; in a liquid medium including-the corresponding I phosphorus-trihalide and ox'y'halide' 4.,A'process of preparinga phosphorus oxyhalide which. comprisesareacting phos Z phorus. and a halogen in a liquid medium ineluding at least-one halogen derivative of phosphorus to forma liquid mixture of phos phoruswpentahalidei and lower halogenated V l phosphorus. derivativesfand then subjecting J the product of such first step to the action of t a compound containinga hydroxyl group in amount equivalent to'the phOsphOrIIspentahalide contained therein, while maintaining the temperature below about70 (1. V -5. A process of preparing aphosphorus oxyhalide which comprises reacting phos-.

phorus and a halogenin' aliquid medium in-;

cluding the". corresponding phosphorus tri halide to form a liquidmixture of phosphorusfpentahalide and lower. halogenatedw' phosphorus derivatives and-then subjecting" the product of such first step to the action ofa compoundcontaining a'hydroxyl group in amount equivalent tothe phosphorus pen: j

'tahalide contained therein, while maintaining the temperature below about 7 0C.

6. l t-process ofpreparing a phosphorus oxyhalidewhich comprises reacting pho F phorusafnd a halogen ina liquid medium including the corresponding phosphorus trihalide and oxyhalide to form a liquid mixture of phosphoruspentahalide' and lower halogenated phosphorus derivatives and then subjecting the product of such first step to the, action of a compound containingga hy-v droxyl group in amount equivalentyto the phosphorus pentahalide contained. thereinQ while maintaining the temperature below about 70'C.- 1 v -7. 'A process of preparing chlorineicome pounds of phosphorus which comprises-re acting phosphorusand chlorine in a liquid medium'including at least onechlorine dee rivative of phosphorus.

8. A process of preparingztchlo rine1compounds ofphosphorus which comprises reacting phosphorus and chlorine inta liquid medium' including phosphorus trichloride;

.9. A process' of I preparingv chlorine com -L pounds of phosphorus which comprises re' sang phosphate and. chlorine inv'a liquid medium, including phosphorus 'trichloride and phosphorug v phosphorus 1 derivatives and r then subjecting of acoinpound containing-a hydroxylgroup in amount equivalent to the phosphorus pentachloride contained therein, hile maintaining the temperature v below about '70 J C. or 11; A "process-=05 preparing phosphorus oxychloride which comprises reacting, phos phorusiand chlorine in'a liquid medium including phosphorus trichloride to'forma liqid mixture c t-phosphorus pentachloride and lower chlorinated; phos'phorus' derivatives it i and then subjecting the product of. hf'fi -St step tothe action ofa .oompound 'containing I a hyd roxyl g'roup'in amountequivalent to the fphosp'hor'us penta'chloride contained whilemaintaining the temperature therein,

-- below" about :70 0.. v

12;;A p'rocess of preparing:phosphorus 7 oxychloride which comprises reacting phos phorusand chlorine in" a liquid medium including; phosphorus .trichloride and phos- 15'. "A---, processjof phosphorus and then separating-the resulting organic oxychloride and an, organic chloride conjoint: -1y, which comprises reacting-"phosphorus and f chlorine in a liquid medium" including at 1 1 least one of the compounds phosphorus ftriv chloride'and phosphorusjoxychloride, adding an alcohol inamount equivalent to the phosi phorus pentachloride thereby formed, while 1 n 7 Lmaintaining the temperature below :7 O Q,

chloride and phosphorus oxychloride by dis tillation from the reactionproductg 7 16. A process i-of preparing phosphorusic oxychloride, which "comprises reacting phos- Vphorius and chlorine in a'liquid mediu nineluding at least one of the compounds phosphorustrichloride and phosphorusoxychloridei'toform-asolut'ion of phosphorus pentachloride, addingater thereto iniarnount equivalent to such pentaohloride, While main- ,taining the temperature beloW'70' C: and

' separating phosphorus oxyichloride'lfroin the i reaction product; r Signed by us thisi6th da'y of J e, 1 29:? s I EDGAR o; BRITTON. I HAROLD I R; sLAeH:

P pho-rus'oxychloride to form a liquid mixture action'fof'a compound containing a hydroxyl ofphosphorus"pentachloride and lower chlo-' rinated phosphorus derivatives and then subjecting thefproduct of such first step to the group in'arnount equivalent to the phos- ,13. A process of. preparing phosphorus oxychloride and an acyl chloride 'conjointly I "phorus; fpentachloride; contained therein Whilefmainta'ining the temperature below] T which comprises reacting phosphorus nd 1 5 chlorine in"a;-'liquid lnedium including at least one ofthe compounds phosphorus trithereto an organic carboxylic acid in amount equivalent to the phosphorus penta-chloride contained therein, while maintaining the temperature' below 6., and then separating the resulting acid chloride and phosphorus chlorideand phosphorus oxychloride; adding oxychlorideby distillation from the reaction product." 7 I 14;. A. process of preparing phosphorus o xjchloride and an acyl ohloride conjointly whlch comprises reacting phosphorus and chlorine in a liquidmediumincluding at least one of the compounds phosphorus trichloride and phosphorus 'oXychloride,-aclding' acetic acid thereto in' arnount equivalent to the phosphorus: pentachloride contained therein, While maintaining the temperaturebelow 70 and then, separating acetyl' chloride" and phosphorus oxychl'ori de by distillation from the reaction'product, l 1 w 95. ios

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